Magazine loaded recoilless gun



April 11,1950 c. D. BURNEY MAGAZINE LOADED .RECOILLESS cum 4 Sheets-Sheet 1 Filed'Sept. 6, 1945 April 11, 1950 c. D. BURNEY MAGAZINE LOADED RECOILLESS GUN 4 Sheets-Sheet 2 Filed Sept. 6, 1945 m m Y m In W m R U B v .D flMB mwN M m v m Ki. x N C O WW m c. D, BURNEY MAGAZINE LOADED RECOILLESS GUN April 11, 1950 4 Shet-Sheet 5 Filed Sept. 5, 1945 'F/GZ y M WY W April 11, 1950 c. D. BURNEY MAGAZINE LOADED RECOILLESS GUN Filed Sept. 6, 1945 4 Sheets-Sheet 4 projectile home in the breech chamber. carrier may be rotated by handwith a step-bystep motion, but for quick firing may be automatically rotated, as, for instance, in a manner similar to the indexing of a capstan lathe turret.

Patented Apr. 11, 195Q MAGAZINE LOADED RECOILLESS GUN' Charles Dennistoun Burney, Bayriards Park; near Cranleigh, England Application September 6, 1945, Serial No. 614,719 In Great Britain October 4, 1943* Section 1, Public Law 690, August 8, 1946 Patentexpires October 4, 1963 The present invention relates to recoil-less guns of-the type forming the subject matter of my lirior but concurrent application for Letters Patent Serial No. 552,347 now Patent No. 2,489,747, and adapted for quick firing with automatic loading in accordance with my applications for Letters Patent Serial Nos: 614,717 and 614,718, filed of even date herewith, and now Patent No. 2,489,954 andnow abandoned, respectively.

In the two last mentioned applications the rearwardly discharging gases for balancing the recoil are discharged through apair of spaced nozzles, extending beyond the breech from lateral enlargements of thejcartridge chamber, the projectiles being loaded into a breech aperture lying between the nozzles, and the charges either being loaded behind the projectiles, or being loaded into the opposite ends of the lateral enlargements in the reverse direction to the projectile;

According to one feature of the present invention, a carrier for a number of projectiles is ro tatably arranged on one of the projecting nozzle members, said carrier having a number of axially extending socketsor holes to receive the pro-jectiles, and the projectiles, loaded into the carrier ata loading point, are carried round step by step until they come opposite tothe breech chamber between the nozzles, when a (to-operating automatic rammingdevice rs actuated to ram the The Broadly therefore the inventioncomprises a recoil less gun or the type specified having a pair of gas discharge nozzles spaced apart, with the breech opening between them, the ammunition being supplied through the medium of a carrier rotatable on one of the gas nozzles and being transferred into the breech from said carrier by a moving breech block reciprocated' by gas pres sure derived from the gun barrel in one direction and a return sprin in the other direction. The carrier may be an annular magazine carrier removable from the nozzle and carrying a plurality of roundsof ammunition disposed peripherally thereof, or the ammunition may be supplied to the carrier 11 Claims. (01-. 89-137) 1 7 According to a further part of the invention the carrier is adapted to be rotated by a pawl and ratchet mechanism operated by the reciprocating breech block mechanism. In one construction, for example, the breech block is carried between the arms of a forked member passing through slots in the breech chamber wall and connected to a piston in a gas cylinder communicating with the barrel bore, whilst the fork arms are engaged in curved grooves in a pair of levers fixedly pivoted at one end and articulated to rods connected to a pair of ratchet pawls at their free ends, one of said pawls being operative through an annular ratchet on the end of the magazine carrier to rotate the carrier on the downward movement of said pivoted levers and the other of said pawls being operative to rotate the carrier on the upward movement of said pivoted levers.-

In order that the invention may be clearly understood and readily carried into practice it isillustrated, by way of example only, in the accompanyi-ngv drawings,- in which:

Figure 1 is a side elevation of an automatically, loaded recoil-less gun of 20 mm. caliber according to this invention;

Figure 2 is a plan view thereof; Figure 3 is a view to a larger scale of the breech end of the gun, showing the magazine operating mechanism only, the breech block and its associated parts being omitted for the sake of clearness;

Figure 4 is a rear elevation diagrammatically;-

showing the magazine and part of its operating mechanism;

Figure 5- is a section showing the breech blockconstruction in detail;

Figure 6 is a partial plan View of the breech- Figure 8 is a detail view in section of the r magazine release device therefor;

Figure 9 is aview of the pawlrotating mechanism for the magazine carrier;

Figure 9a is a view showing the magazine clutch and release mechanism;

Figure 10 isa diagram of the extractor mechanism;

Figure 11 is a sectional diagrammatic View of the double loading step arrangement, and

Figure 12 is a diagram showing a form of ammunition belt suitable for use in connection with the improved gun.

The barrel I is screwed into the breech chamber 2, the rear part of which is fitted with two outwardly inclined nozzles 3, which are spaced vertically apart, to leave a clear space behind the breech opening of the chamber 2. Supported from the breech chamber 2 and the upper nozzle 3, is the breech block guide bracket 4, which is connected to the nozzle 3 by a web dove-tailed into the bracket 4. The rear end of this bracket 4 has pivoted thereto a pair of curved tail levers I5 which extend forwardly towards the breech, and near their ends have pivoted thereto rods It for operating the magazine carrier as hereinafter described.

Mounted above the barrel I is a gas cylinder 6 to which explosion gases are admitted through valve 5 from behind the projectile, as soon as the projectile passes the inlet port of said valve. In the cylinder 6 moves a piston I3 whose spindle I2 extends towards the breech block and forks into a pair of parallel arms II which pass through slots in the breech chamber wall where suitably enlarged by lugs (see Fig. 4). The free ends of fork arms I I are connected to the bracket 9 (Fig. 5) which carries the breech block In, and also carry on their outside surfaces studs I4 which are engaged in longitudinal grooves along the inner surfaces of the curved tail levers I5. Consequently, as the piston I3 reciprocates, the tail levers I5 are depressed and raised owing to the curvature of their slots, to operate the magazine carrier 26 through the pawl mechanism hereinafter described;

The breech block I is of'the rotary interrupted screw type, and. it is of hollow cylindrical box form, with peripheral external screw threads, helices, or parallel collars, Illa, interrupted at several points, as is well-known. Centrally within the breech block is a sleeve IElb in which slides the firing pin which is mounted on bracket 9, which also carries a concentric sleeve 49 adapted to slide within the skirt of the breech block I0. Surrounding the sleeve Iflb, but lying within the sleeve 49 is a spring 5| which acts tomove breech block I0 outwardly on sleeve 49.-

In the outside of wall-49 arehelical grooves 3| which are engaged by pins 30 projecting in- Wardly from the skirt of breech block I0, whilst peripherally the breech block ID carries a pin 52 engaged in a longitudinal groove in guide bracket 4. As the breech block I0 is moved by fork arms II from its extreme rearward position towards the breech the pin 52 prevents relative rotation of breech'block ID in relation to part 49, but when block ID has been introduced into the breech the slot in which pin 52 travels terminates so that block I0 is then free to rotate. The fork arms II still have farther to travel, and this is permitted by spring 5|, but in doing this the helical grooves 3| and pins 30 cause rotation of block I0, which is then freed from the restraint of pin 52. Consequently the divided screw threads, helices or collars of breech block I0 become fully engaged with those in the breech end of chamber 2 and the breech becomes tightly closed; The .finalmovement of fork arms II cause the point of the firing pin 50 to project through theend of sleeve I01) and strike the cartridge percussion cap,- thus firing the gun.

The above movement of the fork arms I l which inserts the ammunition in the breech, closes the breech block, and fires the gun, is effected by the spring 29 (Fig. 2) in which energy is stored during the rearward stroke of the fork, produced by the gas pressure. The spring 29 surrounds a guide rod projecting from breech chamber 2, which enters into a tube I2a extending rear- Wardly from the fork of piston rod I2, the forward end of the spring 29 hearing on the rear end of the tube I2a.

The breech block II] also serves in its forward movement as a rammer for introducing the ammunition into the breech chamber 2, the ammunition being of fixed type, and comprising a cartridge case containing the propellant charge with the projectile fixed at its forward end. Since, however, the present invention is concerned with recoil-less guns in which a large part of the explosive gases is discharged rearwardly through the nozzles 3, the cartridge case must be perforated or of skeleton formation.

The ammunition is fed into the breech from a magazine carrier 26 which is rotatably mounted Within a fixed outer casing 26a on the lower nozzle 3, through the intermediary of a. cylinder 21 attached by a plate 28 to 'th'enozzle' 3. The sheet metalmaga'zine carrier 26 has arcuate spaces or sockets 22ain which the rounds. of ammunition are accommodated, v between. which are rollers 53 adapted to facilitate rota-' tion of the carrier 26 on cylinder 21. At its rear end the magazine carrier 25 has a ring of ratchet teeth 64 (Fig. 9) adapted to be engaged by pawl arms 23 and 23a rotatable about a central pivot 54 on the inside. of plate 28. To these pawlsare connected the free ends of the rods] I6 pivoted. to the tail levers I5; On the rearward stroke, of the fork arms II both pawl levers 23 and 23a, are driven downwards by tail levers I5, and'the. right hand one operativelyv engages a tooth 64 so as to rotate the carrier 26 for an angular distance equal to half the spacing of the ammunition, whilst the left hand pawl rides over the] magazine ratchets. On the return (forward) stroke the tail levers I5 are raised and therewith the pawl arms 23 and 23a are raised, but

this time their functions are reversed, inasmuch. as the left hand pawl will be operative and the I right hand will ride over the ratchets. The car-.

rier 26 will accordingly be carried forwardagain once more, for the same angular distance 'as be-" fore, bringing the next round of ammunition exactly opposite to the breech, ready for ramming, home by the reciprocating. breech 'blo'ck III, as.

already described.

As shown in Figure 7 the pivot 54 round which: the pawls 23 and 23 rotate ishollow. and is'fitted with a push button '25. adapted to be depressed against an internal spring. The free end of'push button rod projecting beyond the pivot 54 has the wall. of cylinder 21.

against a ar-movementm me-"tamer 21, but is permitted freely to rotate- -thereon, to bring one round; afteri another opposite-to the breech for loading and firing until the magazine'is exhausted. The magazine shown in the drawings is designed to hold eight rounds; but obviously it could be designed to hold any desired number of rounds. When themagazin carrier 26 becomes empty it is only necessary to press button 25 to retract shoes 24 and free the empty magazine carrier. for removal andreplacement by-a new fully charged carrier. 1' F. x

It should be understood that when the breech block l first engages a round in the magazine carrier 26 it does not engage axially therewith, but only engages with an upper lip portion thereof, and that as the round moves forwardly into the breech its rear end rises until finally it is axial in relation to the breech block II], when this closes the breech.

The cartridge cases are automatically extracted and ejected by the mechanism illustrated diagrammatically by Figure 10. On each side of the breech ring are pivoted extractors 63, which engage behind the cartridge flange on loading and on the spindles of said extractors are mounted externally of the breech chamber wall angularly directed levers 65 the free ends of which are curved to lie in the paths of lugs or projections 66 on the sides of fork arms I I. The said lugs are so located that the extractors are operated to dislodge the cartridge case and throw it clear of the breech as soon as the breech block I0 has moved substantially to the end of its rearward 7 is illustrated by Figure 11, may be provided. This consists of a telescopic spring plunger 61 housed in the wall of breech chamber 2 and which plunger telescopes within a spring as shown in Figure 11. The spring urges the plunger to the Figure 11 position. The outer end of the plunger is connected to a pivoted dog lever 68, the nose of which, when the lever is raised, engages with a notch 69 in one of the fork arms I I, thus locking the fork against forward movement.

When loading takes place, and during the rearward movement of the breech block III, the dog lever 68 rides along the lower edge of fork arm I I, the spring plunger 61 being yielding to permit this. As soon as the cartridge is extracted the resistance to movement of the lower end of plunger 61 is removed and consequently the dog lever 68 is no longer pressed upwardly and its nose therefore does not engage in notch 69. If, however, for any reason, the round should not be extracted, as soon as the notch 69 passes the nose of dog lever 68, the plunger 61 extends in length and the nose of dog lever 68 engages in notch 69, thus preventing subsequent forward movement of fork arms II, such as is necessary for the next loading action, until the round of ammunition remaining in the breech has been removed.

The gun being recoil-less may be mounted on any form of stationary or mobile mounting or carriage permitting the necessary traversing and elevating movements of the gun.

I claim:

1. In a recoil-less gun, a barrel, a breech casing including a chamber, said breech casing being provided with a loading port opening from the rear or: its" chamber, a breech blodlr movable between breech port closing position and a predetermined position spaced-from closing position, a gas discharge-nozzle communicating with the chamber of the breech casing and'extending rearwardly from the breech casing,'a magazine 'element including pockets for projectiles and rotatableabout-sa-id gas discharge nozzle-to successively position its pockets in the path of closing movement of the breech block, and means operated by the firing of the gun to reciprocate the breech block and rotate said magazine. L;

2. A recoil-less gun of the character described in claim 1 wherein the magazine element is of annular form with its pockets arranged in a circumferential series.

3. A recoil-less gun of the character described in claim 1 wherein the magazine element is removable.

4. A recoil-less gun of the character described in claim 1 including belt means to supply said magazine element with projectiles.

5. A recoil-less gun of the character described in claim 1 including a ratchet device secured to the magazine element and a pawl element secured to the breech block reciprocating means.

6. A recoil-less gun of the character described in claim 1 wherein the breech block reciprocating means includes a piston operable in a gas cylinder communicating with the barrel bore.

'7. A recoil-less gun of the character described in claim 1 wherein the breech block reciprocating means includes a piston operable in a gas cylinder communicating with the barrel bore, and said piston is carried by a piston rod having its rearward portion bifurcated to extend through spaced slots in the breech casing and to pass along opposite sides of the breech block.

8. A recoil-less gun of the character described in claim 1 wherein said magazine supporting gas discharge nozzle is positioned below the breech port and a second gas discharge nozzie is positioned above the breech port.

9. In a recoil-less gun, a barrel, a breech casing including a chamber, said breech casing being provided with a loading port opening from the rear of its chamber, a breech block movable between breech port closing position and a predetermined position spaced from closing position, a gas cylinder on the barrel and in communication with the barrel bore, a piston rod extending from the gas cylinder and rearwardly through the breech casing, a pair of levers pivoted at a point spaced rearwardly of the rear end of the breech casing, said piston rod being operatively connected to said levers so as to move the latter transversely of the breech bore as the piston rod is reciprocated longitudinally of the breech bore, a gas discharge nozzle extending rearwardly from the breech, casing, a magazine rotatable upon the gas discharge nozzle, and a pawl and ratchet connection between said levers and the magazine whereby the magazine will be given a partial rotation upon each movement of said levers.

10. In a recoil-less gun of the character described in claim 1, wherein the breech block is provided with interrupted threads and is rotatable with respect to said breech block operating means, means to hold breech block against rotation during the major portion of its reciprocating movement, interrupted threads in the breech port adapted to engage the threads on the breech block, and means to rotate the breech block while the latter is moving in engagement with the breech port threads. 7 Number 11. A recoil-less gun of the character described 454 403 in claim 10 including a firing pin carried by the 749'214 breech block and means to move said firing pin 5 1 1 135 forwardly after the breech block is rotated into g locked position. 2'122423 1 CHARLES DENNISTOUN BURNEY. 2 1 1 3 REFERENCES CITED m a The following references are of record in the Number file of this patent:

'- UNITED STATES PATENTS Name Date Odkol'ek June 16, 1891 McClean Jan. 12, 1904 McClean Oct. 22, 1912 Redpath et a1 Mar. 25, 1919 Joyce July 5, 1938 Waltke Nov. 12, 1948 FOREIGN PATENTS Country Date Great Britain Jan. 24. 1929 

